W. Va. Code § 29A-3-18
Unless there is a provision in a legislative rule specifying that the provisions thereof shall not be severable, the provisions of every legislative rule, whether enacted before or subsequent to the effective date of this section, shall be severable so that if any provision of any rule section or amendment thereto is held to be unconstitutional or void, the remaining provisions of the rule shall remain valid, unless the court finds the valid provisions are so essentially and inseparably connected with, and so dependent upon, the unconstitutional or void provision that the court cannot presume the Legislature would have enacted the remaining valid provisions without the unconstitutional or void one, or unless the court finds the remaining valid provisions, standing alone, are incomplete and are incapable of being executed in accordance with the legislative intent: Provided, That if any legislative rule has its own severability clause, then that severability clause shall govern and control with respect to that section, in lieu of the provisions of this section. The provisions of this section shall be fully applicable to all future amendments to legislative rules, with like effect as if the provisions of this section were set forth in extenso and every such amendment were reenacted as a part thereof, unless such amendment to the legislative rule contains its own severability clause.
W. Va. Code § 29A-3-18